File photo: Rep. Trent Franks, R-Ariz.,, had said Thursday that he would resign at the end of January but said Friday that his wife’s ailment had prompted him to change his plans and immediately step down.

WASHINGTON – Rep. Trent Franks, R-Ariz., facing an ethics investigation over alleged sexual harassment, announced Friday that he will resign immediately following his wife’s admission to the hospital.

Franks had said Thursday that he would resign at the end of January but said Friday that his wife’s ailment had prompted him to change his plans and immediately step down.

“Last night, my wife was admitted to the hospital in Washington, D.C. due to an ongoing ailment,” he said in a statement. “After discussing options with my family, we came to the conclusion that the best thing for our family now would be for me to tender my previous resignation effective today, December 8th, 2017.”

The Associated Press reported Friday that a former Franks aide said the congressman repeatedly pressed her to carry his child, at one point offering her $5 million to act as a surrogate.

The former staffer said the congressman asked at least four times if she’d be willing to act as a surrogate in exchange for money. Franks, in his statement announcing his resignation, said he and his wife have struggled with infertility.

The Associated Press verified the identity of the staffer, who asked that her name be withheld out of concern for her privacy, and confirmed that she worked in Franks’ office.

On Thursday, the House Ethics Committee said it would create a special subcommittee to investigate Franks for conduct “that constitutes sexual harassment and/or retaliation for opposing sexual harassment.”

The investigation came after House officials learned that he had asked two female employees to bear his child as a surrogate.

Franks acknowledged in a Thursday statement announcing plans to resign Jan. 30 that the investigation concerned his “discussion of surrogacy with two previous female subordinates, making each feel uncomfortable.”

Although Franks’s statement left the circumstances of the “discussion” murky, three Republicans familiar with the allegations said that he had asked the staffers, who worked for him at the time but have since left his office, if they would serve as a surrogate mother for his child. A spokesman for Franks did not respond to a request for comment on that claim.

In his statement, Franks said he never “physically intimidated, coerced, or had, or attempted to have, any sexual contact with any member of my congressional staff.”

“However, I do want to take full and personal responsibility for the ways I have broached a topic that, unbeknownst to me until very recently, made certain individuals uncomfortable,” Franks said, adding, “I deeply regret that my discussion of this option and process in the workplace caused distress.”

Franks explained in his statement that he and his wife have long struggled with infertility. After having twins with a surrogate, the couple sought additional children, he said.